Electronic appliance having housing-case made of biodegradable material, and container made of biodegradable material

ABSTRACT

An appliance comprising a housing-case, a main unit of such appliance and an optional structural member, wherein at least portions of the housing-case and the structural member are made of biodegradable material containing polylactic acid as a major component is provided. Such appliance can achieve durability sufficient for the practical use without causing environmental impact if the housing-case and structural member thereof are disposed as they are.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an electronic appliance using ahousing-case and inner structural members, wherein at least portions ofsuch housing-case and inner structural members are made of biodegradablematerial and the present invention further relates to a container madeof such biodegradable material.

[0003] 2. Description of the Related Art

[0004] For example, electronic appliances are generally put into use forseveral to ten-odd years and disposed thereafter as refuses. At present,such refuses, except those of some large-sized electronic appliances,are not collected nor recycled. In Japan, recycling of the used allianceis not legally regulated. Thus the most of the electronic appliancesbecomes non-combustible refuses after once they are disposed. Evensmall-sized electronic appliances can be a large amount of refuses ifthe marketing volume thereof is huge. This raises a serious problem whenconsidering the recent shortage in the number (or the capacity) of wastedisposal sites.

[0005] Incidentally, when the appliances are disposed, a shreddingprocess is applied as the most popular way of a waste treatment to thewasted appliances. The shredding process, however, cannot provide afundamental solution for the problem, since such waste treatment methodcan only reduce the volume of the refuses, and the refuses will remainintact for tens and hundreds of years if submitted to landfill. If theshredded dust should be recycled as resources, every parts are finelycrashed, and thus even a valuable material such as gold and copper canbe mixed with invaluable materials such as resin, which results indegraded purity of materials to be recycled and a poor efficiency in therecovery.

SUMMARY OF THE INVENTION

[0006] It is therefore a primary object of the present invention toprovide an appliance using a housing-case and inner structural members,wherein at least portions of such housing-case and inner structuralmembers are made of biodegradable material, and further this inventionrelates to a container made of such biodegradable material, because thebiodegradable material is not causative of environmental impact even ifdisposed without any treatment after use.

[0007] According to the present invention, at least portions of astructure of an appliance housed in a housing-case and further acontainer are made of biodegradable material, wherein the thermallydeformable temperature [defined in JIS (Japanese Industrial Standard)K7207] of the biodegradable material is preferably above 50° C. Thebiodegradable material is such a material capable of being degradedthrough the biologic metabolism.

[0008] In this specification, the housing-case means a case for housingan appliance such as an electronic appliance and a member which forms apart of a surface of the appliance, and the structural member means amember to keep the strength of the appliance housed in the housing-case.The container means a case to contain a small part such as a cassettetape, a magnetic disc, etc, and further electronic appliances. Theelectronic appliance includes such as a remote commander and anyelectronic appliance including circuit boards, a drive device, etc.

[0009] In an appliance according to a first embodiment of the presentinvention, it is preferable that at least almost all of top surface of ahousing-case for an appliance are made of biodegradable material andfurther the melt-flow-rate [defined in JIS (Japanese IndustrialStandard) K7207] of such biodegradable material is preferably within 6to 12.

[0010] In an appliance according to a second embodiment of the presentinvention, the appliance comprises a housing-case, a main unit of theappliance and an optional structural member, wherein at least portionsof the housing-case and the structural member are made of biodegradablematerial, and the portion of the biodegradable material and the portionof non-biodegradable material of the appliance are assembled to beeasily separated from each other upon disposal.

[0011] In the appliance according to the second embodiment of thepresent invention, the thermally deformable temperature [defined in JIS(Japanese Industrial Standard) K7207] of the biodegradable material ispreferably above 50° C.

[0012] In an appliance according to a third embodiment of the presentinvention, the appliance is, for example, a remote commander comprisinga printed circuit board and a housing-case to hold the printed circuitboard inside. The remote commander is used to control another electronicappliance placed at a remote location by emitting a control infra-redright. In this case, a light emitting portion of the housing-case ismade of light transmissive biodegradable material and the other portionof the housing-case is made of impact resistive biodegradable material.The thermally deformable temperature of these biodegradable material ispreferably above 50° C.

[0013] In an appliance according to a forth embodiment of the presentinvention, a sheet-like panel having buttons formed on its surface by apress forming process is provided as a part of a housing-case of theappliance, wherein the sheet-like panel is made of the biodegradablematerial.

[0014] In the appliance according to the forth embodiment of the presentinvention, the thermally deformable temperature of the biodegradablematerial for the sheet-like panel is preferably above 50° C., and aconductive film including binder made of the biodegradable material andconductive material is preferably formed on a back surface of eachbutton. The binder is also made of the biodegradable material ofpolyester system and a melting point of the biodegradable material forthe binder is preferably lower than that of the biodegradable materialfor the panel.

[0015] In an electronic appliance according to a fifth embodiment of thepresent invention, the appliance has a housing-case comprising asheet-like panel and a case and both the panel and the case are made ofbiodegradable material and fixed to each other by adhesive made ofbiodegradable material. Preferably each of above described biodegradablematerial has the thermally deformable temperature of higher than 50° C.

[0016] In an appliance according to a sixth embodiment of the presentinvention, the appliance comprises a housing-case, a main unit of theappliance and an optional structural member, wherein at least portionsof the housing-case and the structural members are made of biodegradablematerial containing polylactic acid as a major component.

[0017] The biodegradable material containing polylactic acid as a majorcomponent is a mixture of polylactic acid and the other components,wherein a weight for the other components preferably does not exceed 50%of the total weight. The above mentioned other components preferablycomprise a single or a plurality of materials arbitrarily selected froma group consisting of biodegradable organic compound other thanpolylactic acid and inorganic compound (magnesium hydroxide, talc,carbon, iron oxide, etc).

[0018] The organic compound other than polylactic acid is a single or aplurality of materials arbitrarily selected from a group consisting ofpolybutylene succinate, polycaprolactone, aliphatic polyester(polyhydlactic acid, for example), cellulose acetate-base biodegradableresin, polyvinyl alcohol and natural organic substances (paper, pulp,natural rubber, glue, lacquer, etc.). Preferably the biodegradablematerial includes only polylactic acid, and the process for disposalbecomes more easy and thereby environmental pollution by the disposal iseasily avoided.

[0019] In the appliance of the present invention, the main unit of theappliance is fixed in the housing-case by screwing, fitting, or adhesionusing adhesive so as to allow easy separation of the housing-case fromthe main unit of the appliance, so that it can readily be separated intothe biodegradable members and the non-biodegradable members. In theappliance of the present invention, the push buttons for operating theappliance are provided on the surface of the housing-case, and thesepush buttons are preferably made of the biodegradable materialcontaining polylactic acid as a major component.

[0020] A container according to a seventh embodiment of the presentinvention, at least a part of the container is made of biodegradablematerial containing polylactic acid as a major component.

[0021] The container of this invention and the appliance of the presentinvention are preferably constructed as follows.

[0022] 1) The biodegradable material containing polylactic acid as amajor component is a mixture of polylactic acid and other component,wherein a weight of the other component preferably does not exceed 50%of the total weight.

[0023] 2) The above mentioned other component comprises a single or aplurality of materials arbitrarily selected from a group consisting ofbiodegradable organic compound other than polylactic acid and inorganiccompound (magnesium hydroxide, talc, carbon, iron oxide, etc.).

[0024] 3) The organic compound other than polylactic acid is a single ora plurality of materials arbitrarily selected from a group consisting ofpolybutylene succinate, polycaprolactone, aliphatic polyester(polyhydlactic acid, for example), cellulose acetate-base biodegradableresin, polyvinyl alcohol and natural organic substances (paper, pulp,natural rubber, glue, lacquer, etc.).

[0025] 4) The biodegradable material containing polylactic acid as amajor component is composed only of polylactic acid.

[0026] 5) The main unit of the appliance is fixed to the housing-case byscrewing, fitting, or adhesion using an adhesive so as to be easilyseparated from the housing-case.

[0027] 6) The container is transparent or semi-transparent in some case.

[0028] 7) When a movable cover is provided, decomposition ordisassembling of the housing-case or the container will become more easyby supporting the movable cover with a pivot bearing in a rotatablemanner so as to allow the cover to turn around the pivot bearing and tobe fitted to the housing-case or the container to close it.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In the accompanying drawings:

[0030]FIG. 1 is a table showing test results of heat resistance andmoisture resistance of sheets made of various biodegradable materials;

[0031]FIGS. 2A and 2B are charts showing a method for measuring bendingcharacteristics of a test sample;

[0032]FIG. 3 is a table showing test results of bending characteristicsbased on the method as shown in FIGS. 2A and 2B;

[0033]FIG. 4 is a table showing test results of touch of click anddurability of circular projections fabricated from the above sheets andused as push buttons;

[0034]FIG. 5 is a table showing measurement results of lighttransmissivity of the individual materials;

[0035]FIG. 6 is an exploded perspective view of a remote commander ofone of embodiments of the present invention;

[0036]FIG. 7 is a sectional view of one of embodiments of a laminatedstructure of a push button;

[0037]FIG. 8 is a table showing film property of a film with regard toweight % ratio of binder and carbon; and

[0038]FIG. 9 is an exploded perspective view of a sleeve-type case for aMini Disc player of another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0039] In accordance with the present invention, a housing-case of anappliance, optional structural members of the appliance, and a containerfor an appliance are made of biodegradable material. If possible, it is,of course, the best way to use the biodegradable material to all of thehousing-case, the optional structural members and other parts of theappliance. But it is practically very difficult to make all members andelectronic parts with the biodegradable material, technically.

[0040] Accordingly, the housing-case occupying major part of theappliance and the container for an appliance, for example, arepreferably made of the biodegradable material containing polylactic acidas a major component. In assembling the appliance and the container,those housing-case and the container are so constructed that thebiodegradable material and the non-biodegradable material of thosehousing-case and the container are easily separated from each other upondisposal. Accordingly, the biodegradable material and non-biodegradablematerial of the appliance and the housing-case can be easily processedfor a recycling process.

[0041] Further in the appliance such as an electronic appliance of thepresent invention, the housing-case and the top surface of thestructural member are preferably made of the biodegradable material.Namely, at least the top surface of the housing-case and/or thestructural member of the electronic appliance such as a radio, amicrophone, a portable TV, a keyboard, a head-phone stereo, a telephone,a cassette-radio, an earphone, etc are made of the biodegradablematerial. In one case, the biodegradable material may be coated orsprayed on the top surface of the housing-case of the electronicappliance. Namely, in the electronic appliance, the top surface of thehousing-case is formed as a layered structure having much biodegradablematerial than inner part of the housing-case. As the biodegradablematerial is harmless to human body than conventional resin material, theelectronic appliance having the housing-case covered with thebiodegradable material becomes more safe than conventional appliances.

[0042] In order to use the biodegradable material as the housing-caseand the structural member of the electronic appliance, followingspecifications are required for the biodegradable material. Namely, thethermally deformable temperature of the biodegradable material ispreferably above 50° C. Further the melt-flow-rate of the biodegradablematerial is preferably within 6 to 12 in consideration of easiness for amold-forming process. Further it is desirable that the biodegradablematerial does not change the physical property after being placed in anatmosphere of 60° C. in temperature and 80% in humidity during 24 hours.

[0043] In the appliance and the container of the present invention, thebiodegradable material containing polylactic acid as a major componentmay be a mixture of polylactic acid and other component, and the othercomponent may be a single or a plurality of additives arbitrarilyselected from a group consisting of lubricant, flame retardationproviding agent, flame retarder, ultra-violet absorber, antioxidant,coloring agent, antistatic agent, sound insulation providing agent, heatresistance providing agent, abrasion resistance providing agent, andreinforcing fiber.

[0044] Specific examples of the additives are shown below:

[0045] (1) lubricant such as zinc stearate and butyl stearate;

[0046] (2) flame retardation providing agent such as talc;

[0047] (3) flame retarder such as magnesium hydroxide and aluminumhydroxide;

[0048] (4) ultraviolet absorber such as phenyl salicylate;

[0049] (5) antioxidant such as 1,1,3-tris(2-methyl-4-hydroxy-5-t-buthylphenyl) butane;

[0050] (6) coloring agent such as inorganic pigment, organic pigment anddye;

[0051] (7) antistatic agent such as alkylimidazoline;

[0052] (8) sound insulation providing agent such as iron oxide;

[0053] (9) heat resistance providing agent such as talc;

[0054] (10) abrasion resistance providing agent such as graphite; and

[0055] (11) reinforcing fiber such as inorganic high-strength fiber andorganic high-strength fiber.

[0056] The construction of the present invention is explained withreference to test results and various embodiments as follows.

[0057] Of course certain levels of characteristics and physicalproperties are required for the housing-case of the appliance and thecontainer of the present invention since material characteristicsindividually required for the housing-case or the container thereof arealready defined. Thus the inventors of this invention examined to findout biodegradable materials suitable for use in the housing-case forappliances, structural members and containers for containing appliances,cassette tapes, discs, etc.

[0058]FIG. 1 shows test results of heat resistance and moistureresistance of sheets of 0.1 mm thick made of various biodegradablematerials (biodegradable resin). As for polylactic acid, two products (Aand B) obtained from different manufacturers were used, both of whichproved superior heat resistance and moisture resistance than the othermaterials as shown in FIG. 1.

[0059] The bending characteristics of sheets were measured asdeterioration of physical property after the heating. As shown in FIG.2A, a rectangular test sample S having dimension such as 7 (width)×50(length)×2 (thickness) mm, for example, was placed on a test desk 50.One end of the test sample S was directly placed on the test desk 50 andthe other end of the test sample S was placed on the test desk 50 by wayof a support member 51 having a height of 15 mm. The test sample S wasplaced in an atmosphere of 80° C. in temperature and a humidity-free inhumidity during 24 hours together with the test desk. After taking outthe test sample from the above mentioned atmosphere, a dislocation B (asshown in FIG. 2B) of the test sample S was measured, and the dislocationB was defined as the bending characteristics.

[0060]FIG. 3 shows test results of the bending characteristics for threetypes (A, B and C) of source resin. A source material for thehousing-case and the container preferably have to show the dislocation Bbelow 1.0 mm in the bending characteristics.

[0061]FIG. 4 shows test results of touch of click and durability ofcircular projections of 7 mm in diameter and 0.5 mm in height,fabricated by press forming the above sheets and used as push buttons.The reason why the above tests were conducted is that the sheetmaterials are often fabricated into such form composing the surface ofelectronic appliances and used as push buttons. The test resultsrevealed that polylactic acid have rigidity in an appropriate range andalso have desirable durability.

[0062]FIG. 5 shows measurement results of light transmissivity of theindividual materials. When these materials are intended for use inappliances, it is necessary to confirm not only the transparency in thevisible wavelength region but also the transmissivity at 900 nm oraround to allow communication in the infrared wavelength region. Asclearly known from the FIG. 5, the polylactic acid showed hightransmissivity in both wavelength regions.

[0063] While other physical properties such as impact resistance,tensile strength and formability need be considered, these can readilybe obtained by various known information sources such as material datasheets distributed by manufacturers of such resins, and from whichsuperiority of the polylactic acid can readily be confirmed. Since thepolylactic acid was thus found to be excellent in every physicalproperties, the present inventors then used these materials to makeprototypes.

[0064] Next, the present invention embodied as a remote commander willbe explained. FIG. 6 is an exploded perspective view showing an overallstructure of the remote commander for television sets, video taperecorder or the like. The remote commander 1 comprises a sheet-typepanel 2, a case 3, a filter 4, a mounting board or printed circuit board5 and screws 6 for fixing the mounting board 5 to the case 3. The panel2 and the case 3 together constitutes a housing-case, and the filter 4also serves as a structural member. The panel 2, the case 3 and thefilter 4 are made of biodegradable resin containing polylactic acid as amajor component. The filter 4 is fixed to the case 3 by engagingprojected portions 4 a thereof with hole portions 3 a provided on thecase 3. The mounting board 5 is fixed to the case 3 by means of thescrews 6 as described before. The panel 2 is fixed to the mounting board5 with the aid of adhesive coated on the rear surface of the panel 2 soas to allow easy peel-off from the mounting board 5.

[0065] When the remote commander 1 is to be disposed, at first the panel2 is peeled off from the mounting board 5, the filter 4 is disengagedfrom the case 3, and then the screws 6 are loosen to separate thehousing-case members (the panel 2 and the case 3) made of thebiodegradable resin and the mounting board 5 made of non-biodegradablematerial. The total volume of the housing-case is approx. 3 times largerthan that of the mounting board 5 in general, so that fabricating theentire part of the housing-case with the biodegradable resin cansuppress the volume of parts to be recycled as small as ¼ of that of theconventional remote commander.

[0066] The method for fabricating parts of the remote commander 1 isexplained next. The case 3 and the filter 4 are formed by an injectionmolding process. In this case, impact resistive source resin is used tothe case 3 and light transmissive source resin is used to the filter 4,because the infra-red light emitted from inside of the remote commander1 has to transmit the infra-red light through the filter 4. To be moreconcrete, talc or magnesium hydroxide is add to polylactic acid forreinforcing impact resistivity of the source resin for the case 3, andpure polylactic acid are used to add to the source resin for the filter4. Further in order to put black color to the case 3, carbon black(powder) is added to the polylactic acid. As coloring agent, iron oxideother than the carbon black is preferable because those materials do notyield environmental pollution after the biologic metabolism.

[0067] Further a construction of the panel 2 is explained more detailwith reference to FIG. 7, wherein the figure shows a sectional view ofthe panel, and particularly a laminated structure of a push button as amain part of the panel 2. Namely the panel 2 comprises a dome-shapedpush button 30 and a substrate 31 supporting the push button 30 fixed byadhesive 32. The adhesive 32 is preferably made of a mixture of naturalresin and latex of natural rubber.

[0068] The push button 30 comprises a spacer 33 made of polybutylenesuccinate having a thickness of 125 μm and a button body 20 laminated onthe spacer 33 by adhesive 34. The adhesive 34 is also made of a mixtureof natural resin and latex of natural rubber.

[0069] In this button body 20, an outer-most layer 37 is a polylacticacid film (a sheet made by a 2-axis drawing process) having a thicknessof 100 μm. A printed layer 36 is formed by printing acryl-base resinusing a screen printing process on a back side of the outer-most layer37 and further a laminate film 35 of polybutylene succinate having athickness of 20 μm and a conductive film 38 are laminated in this orderon the printed layer 36. The conductive film 38 is made of carbon blackadded polybutylene succinate and the printing layer 36 has printeddisplays for the operation of the remote commander by the screenprinting process. The laminate film 35 serves to protect the printinglayer 36.

[0070] According to this embodiment as described above, polylactic acidis used as a material for the outer-most layer 37, and polybutylenesuccinate having lower thermally deformable temperature than that of thepolylactic acid is used as not only a material for the laminate film 35but also a binder for the conductive film 38. Accordingly when thedome-shaped member for the push button is formed by pressing thepolylactic acid, simultaneously films such as the conductive film 38 areable to be thermally fixed. In this case, the temperature for the pressprocess is preferably set to be 80° C. to 100° C., where the polylacticacid does not thermally deformed and the polybutylene succinatethermally deforms enough to attain the above mentioned thermal-fixing.

[0071] In addition, in the above mentioned conductive film 38, thecarbon black is used as the conductive material, so that the pollutionproblem can be avoided if the conductive film 38 is organicallymetabolized together with the panel 2. In this embodiment, thepolybutylene succinate is used as the binder, but other biodegradablematerial such as polylactic acid can be employed. Further in case offabricating the conductive film 38, after making an emulsion by mixingand dispersing powder of carbon black in the solution of polybutylenesuccinate resin dissolved chloroform, the emulsion was painted on aglass plate to have a painted film having a proper thickness. Thus theconductive film 38 was obtained by peeling off the painted film from theglass plate after a drying process.

[0072] The relation of the weight % of the polybutylene succinate as thebinder and the carbon black powder relative to the film property isshown in FIG. 8.

[0073] According to the embodiment of this invention, the weight % forthe binder and the carbon was preferably selected to be {fraction(1/15)}. further a thickness of the conductive film 38 was preferablyset to be 90 μm to 140 μm. And an ohmic value of the conductive film 38was set to be 70 Ω/cm to 100 Ω/cm.

[0074] In the above described example, the mixture of natural resin andlatex of natural rubber was applied to the above mentioned adhesives 32and 34, but in stead of these, polylactic acid, aliphatic polyester suchas polybutylene succinate, polycaprolactone and polyhydlactic acid,cellulose acetate-base biodegradable resin and polyvinyl alcohol can beused as a biodegradable adhesive. Further as a source material for theadhesive, molecular-weight reduced high polymeric material such as usedas a panel or a sheet can be used. Further blended natural material suchas natural rubber and polylactic acid is also can be used as adhesivematerial, and if the material for the adhesive is aliphatic polyesterhaving a melting point of less than 100° C., it can be used as hot meltadhesive, solution adhesive or solvent adhesive.

[0075] In the panel 2 in FIG. 7, all of constructing members such as theadhesive 32, the spacer 33, the adhesive 34, the laminate film 35 theouter-most layer 37 and the binder for the conductive film 38 are madeof the biodegradable materials, except the substrate 31 and the printedlayer 36.

[0076] Next, the present invention embodied as a container for carryingvarious parts will be explained. FIG. 9 is an exploded perspective viewof a container 11 for carrying a Mini Disc (Trade Mark) 14 for recordingmusic. The container 11 comprises only of an upper case 12 and a lowercase 13. Thus the entire body of the container 11 can be made of thebiodegradable resin containing polylactic acid as a major component.While the container 11 may sometimes be disposed with the Mini Disc 14housed therein, the Mini Disc 14 and the container 11 can readily beseparated.

What is claimed is:
 1. An appliance comprising: a housing-case; a mainunit of said appliance; and an optional structural member; wherein atleast portions of said housing-case and said structural member are madeof biodegradable material having a thermally deformable temperature ofmore than 50° C.
 2. The appliance as claimed in claim 1, wherein atleast top surface of the housing-case are made of the biodegradablematerial.
 3. The appliance as claimed in claim 1, wherein melt-flow-ratefor the biodegradable material is set to be from 6 to
 12. 4. Anappliance comprising: a housing-case; a main unit of said appliance; andan optional structural member; wherein at least portions of saidhousing-case and said structural member are made of biodegradablematerial, and the appliance being so constructed as to be easilyseparated the biodegradable material portion and the non-biodegradablematerial portion.
 5. The appliance as claimed in claim 4, wherein athermally deformable temperature for the biodegradable material is setto be more than 50° C.
 6. An electronic appliance to control anappliance located at a remote location by emitting a light controlsignal comprising: a printed circuit board; and a housing-case toenclose said printed circuit board, wherein a portion of saidhousing-case being made of light transmissive biodegradable material andthe other portion of the housing-case being made of impact-resistivebiodegradable material.
 7. The electronic appliance as cited in claim 6,wherein a thermally deformable temperature for both the lighttransmissive biodegradable material and the impact-resistivebiodegradable material are set to be more than 50° C.
 8. An electronicappliance having a sheet-type panel as a part of a housing-case, inwhich a plurality of buttons formed by a press forming process areprovided on top surface of said sheet-type panel, wherein saidsheet-type panel is made of biodegradable material.
 9. The electronicappliance as cited in claim 8, wherein a thermally deformabletemperature for the biodegradable material is set to be more than 50° C.10. The electronic appliance as cited in claim 8, wherein a conductivelayer having conductive material and binder made of biodegradablematerial is formed on a backside on the buttons of said sheet-typepanel.
 11. The electronic appliance as cited in claim 10, wherein saidbinder is made of polyester-base biodegradable material.
 12. Theelectronic appliance as cited in claim 10, wherein a melting point ofthe polyester-base biodegradable material used as the binder being lowerthan a melting point of the biodegradable material used to saidsheet-type panel having plurality of buttons.
 13. An electronicappliance having a housing-case comprised of a sheet-type panel and acase, wherein both said sheet-type panel and said case are made ofbiodegradable material, and said sheet-type panel and said case arefixed to each other by adhesive made of biodegradable material.
 14. Theelectronic appliance as claimed in claim 13, wherein a thermallydeformable temperature for the biodegradable material is set to be morethan 50° C.
 15. An electronic appliance comprising: a housing-case; amain unit of said electronic appliance; and an optional structuralmember, wherein at least portions of said housing-case and saidstructural member are made of biodegradable material containingpolylactic acid as a major component.
 16. The electronic appliance asclaimed in claim 15, wherein the biodegradable material containingpolylactic acid as a major component is a mixture of polylactic acid andother component, where weight % of said other component does not exceed50% of the total weight.
 17. The electronic appliance as claimed inclaim 16, wherein said other component comprises a single or a pluralityof materials arbitrarily selected from a group consisting ofbiodegradable organic compound other than polylactic acid and inorganiccompound.
 18. The electronic appliance as claimed in claim 17, whereinsaid organic compound other than polylactic acid is a single or aplurality of materials arbitrarily selected from a group consisting ofpolybutylene succinate, polycaprolactone, aliphatic polyester, celluloseacetate-base biodegradable resin, polyvinyl alcohol and natural organicsubstances.
 19. The electronic appliance as claimed in claim 15, whereinsaid biodegradable material containing polylactic acid as a majorcomponent is composed only of polylactic acid.
 20. The electronicappliance as claimed in claim 15, wherein said main unit of saidelectronic appliance is fixed to the housing-case by screwing, fitting,or adhesion using an adhesive so as to allow easy peel-off from saidhousing-case.
 21. The electronic appliance as claimed in claim 15,wherein said housing-case has on the surface thereof push buttons foroperating said main unit of the electronic appliance, and said pushbuttons being made of biodegradable material containing polylactic acidas a major component.
 22. A container for housing an appliance, whereinat least a part of said container is made of biodegradable materialcontaining polylactic acid as a major component.
 23. The container asclaimed in claim 22, wherein the biodegradable material containingpolylactic acid as a major component is a mixture of polylactic acid andother component, where weight % of said other component does not exceed50% of the total weight.
 24. The container as claimed in claim 23,wherein said other component comprises a single or a plurality ofmaterials arbitrarily selected from a group consisting of biodegradableorganic compound other than polylactic acid and inorganic compound. 25.The container as claimed in claim 24, wherein said organic compoundother than polylactic acid is a single or a plurality of materialsarbitrarily selected from a group consisting of polybutylene succinate,polycaprolactone, aliphatic polyester, cellulose acetate-basebiodegradable resin, polyvinyl alcohol and natural organic substances.26. The container as claimed in claim 22, wherein said biodegradablematerial containing polylactic acid as a major component is composedonly of polylactic acid.
 27. The container as claimed in claim 22,wherein said container comprises of at least a first case and a secondcase, and said first case and the second case are engaged to each otherby screwing, fitting, or adhesion using an adhesive so as to allow easypeel-off from each other.
 28. The container as claimed in claim 22,wherein said container is transparent or semi-transparent.